It's even more complicated. German law treats the grid as "copper plate", and ignores all regional differences. If a wind park in Northern Germany offers electricity for 8 ct/kWh, then a consumer in Southern Germany is allowed to buy that power and is entitled to get it delivered via the grid. And if the grid can't handle the load because of weak interconnectivity, then a gas turbine in Southern Germany will start and generate the power for 18 ct/kWh, but the consumer only pays 8 ct. The 10 ct/kWh difference is paid by all consumers with higher energy prices.
For Southern Germany, this is quite the deal, because they can now operate expensive gas turbines, and get them subsidized at least in part by electricity consumers in Northern Germany with higher energy prices, while the cheap energy generated in Northern Germany is switched off, as the energy on the books is sold already, but the electricity is generated somewhere else. But because Southern states profiteer from the situation right now, there is much resistance to changes in the law, which would make energy in the South more expensive, while Northern states would get a relief.